1. Field of the Invention
The present invention relates to a fluid bearing, and more particularly to a fluid bearing in which a thrust bearing is mounted at both ends of a rotary shaft to minimize movement and oscillation of the rotary shaft regardless of a thrust load.
2. Description of the Related Art
Recently, with improvements in the information and multimedia industries, there has been a trend to advance the technologies of computer systems, cassette tape recorders, camcorders, and the like. In particular, a hard disk driving gear has been developed, which acts as an auxiliary memory of computer systems and has an extremely fine clearance between a rotary disk and a head which detects a sector of a rotary disk. For this reason, oscillation of a rotary shaft in the hard disk driving gear may be fatal to the rotary disk in which a variety of important data are stored. Therefore, the hard disk driving gear requires high accuracy with minimum oscillation of the shaft. In this respect, a bearing in the hard disk driving gear, which is capable of rotating relative to the shaft at high accuracy is desired. A fluid bearing has been particularly used, which minimizes movement and oscillation of the shaft even if the shaft rotates at high speed.
However, in the conventional fluid bearing apparatus, in order to avoid oscillation or movement of the rotary shaft, a fluid bearing is provided at only one end of the shaft to support a vertical thrust load. As a result, the conventional fluid bearing apparatus has several problems in the case that the shaft does not support the vertical thrust load.
For example, in a horizontal hard disk the apparatus is mounted in the vertical direction and in a driving gear, such as a camcorder or a small sized tape recorder, the thrust load of the rotary shaft is freely varied from the vertical direction to the horizontal direction or from the horizontal direction to the vertical direction. In these cases, the load of the rotary shaft is varied to move the rotary shaft in a vertical direction or a horizontal direction so that the rotary body mounted in the rotary shaft moves. As a result, in the driving gear such as the hard disk which requires high accuracy, there results in fatal problems that the rotary disk is scratched or damaged by contact between the rotary disk and the head which moves separated from the rotary disk at a fine interval.